Apparatus for article packaging



g- 1965 R. s. ZEBARTH ETAL APPARATUS FOR ARTICLE PACKAGING OriginalFiled April 6, 1959 4 Sheets-Sheet I 17, 1965 R. s. ZEBARTH ETAL3,200,562

APPARATUS FOR ARTICLE PACKAGING Original Filed April 6, 1959 4Sheets-Sheet 3 Aug. 17, 1965 R. s. ZEBARTH ETAL APPARATUS FOR ARTICLEPACKAGING Original Filed April 6, 1959 United States Patent 3,200,562APPARATUS FOR ARTICLE PACKAGING Ralph S. Zebarth, Kansas City, RichardL. Lewis, Independence, and Drexel T. Carlson, Kansas City, Mo,assignors to Gordon Johnson Company, Kansas City,

Mo., a corporation of Missouri Original application Apr. 6, 1959, Ser.No. 804,481, now Patent No. 3,071,906, dated Jan. 8, 1963. Divided andthis application Aug. 24, 1962, Ser. No. 21?,166

14 Claims. (Cl. 53184) This is a division of my copending application,Serial No. 804,481, filed April 6, 1959, and entitled Method for ArticlePackaging, now Patent No. 3,071,906, issued January 8, 1963.

This invention relates to novel apparatus for packaging articles ofmerchandise such as poultry.

It has been found advantageous in recent years to package consumerproducts in films of synthetic resin materials, not only because of theinexpensive nature of the packaging procedure but also because the finalpackage is more attractive than heretofore provided units and thecustomer may view the product through the normally transparent film.However, serious problems have been encountered in the provision ofpackages which are sealed from the ambient atmosphere and which arecapable of adequately protecting the product contained therein duringsubsequent handling and sale of the packaged product. The problem hasbeen especially acute in the poultry processing industry wherein it isdesirable that fowl such as chickens be packaged in an attractivecontainer which permits the customer to view the product, yet is ofsufl'icient inherent strength to protect the product, notwithstandingthe fact that the same may be relatively easily bruised or puncturedduring handling thereof, and which also retains fluid integrity againstentrance of air into the container or body fluids and water out of thecontainer.

Another difficulty which has arisen is the tendency of frost to form onthe outer surface of the poultry during freezing of the same subsequentto processing and which occurs unless the film presenting the containersubstantially firmly engages the entire exposed surface of the bird orthe like. Although the relatively flexible and pliable filmsconventionally available do engage sufiicient areas of the poultry toprevent the frosting set forth above, these films are unsatisfactoryfrom the standpoint of being relatively easily broken or torn, as wellas punctured during subsequent handling of the product and, therefore,air is permitted to enter the container, and body fluids may readilyleak from the container upon thawing of the product.

In other instances, the poultry is not frozen prior to distribution andin this situation the flexible and pliable films referred to above arelikewise not of utility because of the ease in which the same may beruptured and thereby causing the deleterious results referred to above.

Prior attempts have been made to seal poultry products and the likewithin synthetic resin films of relatively rigid characteristics, butthese efforts have not met with success primarily because of the factthat the parts of the container did not firmly engage substantially theentire outer surface of the birds and furthermore, it was virtuallyimpossible to adequately seal the container so that the same did notleak during later handling and sale of the packages.

Another factor contributing to leakage of the prior sealed packagesutilizing either flexible and pliable films or the more rigid materials,was the problem of folds and irregularities in the film resulting fromthe latter being folded about the product and then suitably sealed "iceeither in conjunction with a laminated backing board or simplyheat-sealed against one surface of the product.

it is, therefore, the most important object of the present invention toprovide an improved apparatus for permitting packaging of products suchas poultry in a manner so that the birds are protected during handlingand sale thereof and with the packages presenting an attractiveappearance, whether the products are merely chilled or frozen beforemarketing display therof.

A further important object of the invention includes the provision ofimproved apparatus for sealing articles in the nature of poultryproducts within a container which is resistant to admittance of airthereinto or leakage of fluids from within the container, despiterelatively rough handling of the package.

A still further important object of the invention is to provideapparatus for packaging poultry products adapted for being employed topackage all varieties of poultry and which is especially useful forchickens, with the container components of standard size and yetdesigned to package birds of different Weight without modification ofthe packaging apparatus, the method of operating the same or the partsof the container itself.

An important aim of the invention is to provide appa ratus for packagingpoultry products wherein containers of standard size may be employed forchickens of different weights by virtue of the lid of the containerbeing telescoped over the tray portion thereof to an extent de-' pendentupon the size of the bird, and with the material from which thecontainer is formed being characterized by the property of shrinkingunder the influence of heat whereby extraneous flange portions of thecontainer components which would normally remain after placement of thepoultry within such container may be avoided by the simple expedient ofsubjecting such extraneous flange portions to suflicient heat to shrinkthe same and at the same time melt the synthetic resin material andproduce a fluid-tight seal as opposed, melted areas of the containercomponents flow together.

An additional important object of the invention is to provide apparatusfor packaging poultry products in a container of the defined characterwhich is substantially automatic in operation and requiring very littlephysical effort other than placement of the package to be sealed withinthe machine, and followed by actuation of suitable switch mechanism. Asa result, the packaging operation is eflicient and effective at aminimum unit cost.

It is also an important object of the invention to provide improvedapparatus for sealing opposed components of the package container havingmechanism for causing the thermoplastic, heat-shrinkable, syntheticresin material from which the container is constructed to be subjectedto a preheating phase sufficient to soften the material without causingsubstantial shrinking or melting of the latter, whereupon movement ofthe areas of the container to be sealed into engagement with a heatingelement produces a more effective and fluid-tight seal by virltue of theinitial softening of the thermoplastic materia In the drawings:

FIGURE 1 is a front elevational view of apparatus for heat-sealing thepackage container, with portions of the apparatus being broken away toreveal details of guide structure therewithin for verticallyreciprocable ram structure;

FIG. 2 is a plan view of the apparatus shown in FIG. 1 with certainportions of the ram mechanism thereof being broken away to revealdetails of the containerreceiving shiftable platen carried by the mainhousing of the apparatus;

FIG. 3 is a fragmentary, enlarged, vertical, crosss a sectional viewtaken suhstantinally on the irregular line 3-3 of FIG. 2 and looking inthe direction of the arrows;

FIG. 4 is a fragmentary, enlarged, vertical, cross-sectional view takenon line 44- of FIG. 1;

FiG. 5 is a fragmentary, enlarged, vertical, crosssectional view takenon line 5--5 of FIG. 3, looking in the direction of the arrows, andillustrating the ram structure at the uppermost end of the normal pathof travel thereof;

FIG. 6 is a fragmentary, enlarged, cross-sectional view similar to FIG.5 but showing the ram structure intermediate the ends of the path oftravel thereof and substantialiy at a preheat position;

FIG. 7 is a fragmentary, enlarged, vertical, cross-sec" tional view onthe same line as FIGS. 5 and 6 and illustrating the ram structure at thelowermost end of the path of travel thereof;

FIG. 8 is a fragmentary, enlarged, vertical, cross-sectional view on thesame line as FIG. 7 but illustrating in greater detail, the transverse,cross-sectional configuration of the heating element and associatedcomponents for heat-sealing the article package;

FIG. 9 is a reduced, exploded perspective view of the two components ofthe article container and indicating how the same may be moved intotelescoped relationship to enclose the article to be packaged;

FIG. 10 is a schematic representation of the mechanism forming a part ofthe sealing apparatus and serving as means for causing the apparatus toautomatically perform one cycle of operation upon actuation of themechanism;

FIG. 11 is a fragmentary, plan view of one of the heating elementsassociated with the ram structure and the electrical resistance unitsfor raising the temperature of the element being shown in dotted lines;and

FIG. 12 is a fragmentary, enlarged, horizontal, cross sectional viewsubstantially on line 1212 of FIG. 7 and looking in the direction of thearrows.

A novel container particularly adapted to be employed with the presentapparatus in the packaging of products such as dressed poultry andespecially chickens, is broadly numerated It) in the drawings andpreferably comprises a pair of preformed members 12 and 14 adapted to bemoved into telescoped relationship as shown in FIG. 5,

in order to enclose the product to be packaged. Mem- I bers 12 and 14,which are in the nature of a lid and tray respectively, are of athermo-plastic, heat-shrinkable, synthetic resin material of sufficientthickness and characterized by the property of presenting aself-sustaining container component upon forming of the initially sheetma terial into the configuration illustrated in FIG. 9. Tray 1 forexample, is of rectangular shape and provided with a bottom 18 integralwith an upstanding side wall and thereby presenting a cup-shapedcompartment for receiving the article to be packaged, such as a dressedchicken or the like. Although tray 14 is relatively selfsustaining byvirtue of the synthetic resin material employed in production of thesame, it is to be preferred that a series of radially extending ribs 22be formed in bottom 18 and side wall 20 to reinforce the same.Downturned flange portion 24 of tray 14, integral with the uppermostmargin of side wall 2%), serves as the marginal portion of the samewhich is adapted to be melted to provide a seal between lid 12 and tray14. An especially important feature of flange 24 is the provision of oneor more elongated indentations 26 extending longitudinally of respectiverectilinear stretches of flange 24 and thereby minimizing the tendencyof such straight stretches of flange 24 to bow longitudinally thereof.Also, it is to be preferred that side wall 20 of tray 14 flareoutwardly, as best shown in FIG. 5, while flange 24 also flaresoutwardly from side wall 29 to present a substantially trapezoidal spacebetween opposed surfaces of side wall 24} and flange 2 In this way, aplurality of trays 24. may be disposed in stacked, telescopedrelationship prior to utilization of the same for packaging purposes andthereby maintaining the storage'space for trays 14 at a minimum prior toutilization of the same. p

Lid 12 is also preformed of a thermoplastic, heatshrinkable, syntheticresin material preferably the same as that from which tray 14' isformed. The central, substantially rect'angulararea -28 'of lid 12 isformed to substantially conformto the normal upper surface configurationof a dressed chicken and-therefore, has a pair of raised areas at oneend thereof presented by a depression between the same and therebyconforming to the breast of the bird, while the remaining surface ofarea- 28 slopes downwardly and includes spaced, raised areas at the endthereof which is adapted to conform to .the thighs and upper legs of thebird. Since lid 12 is relatively self- .sustaining, it can be recognizedthat when area 28 is preformed to the configuration of the upper surfaceof the bird, the inner face of area 28 substantially conforms to thebird and moves into tight engagement therewith during the packagingoperation to be described in greater de-- tail hereinafter.

Lid 12 has a laterally extending, peripheral section 39 integral withthe margin of area 28, as well as a downturned, outer peripheral skirtportion 32 which is flared outwardly and of suflicient size tocomplementally receive flange 24 of .a tray 14. Again, it is to be notedthat the outwardly flared disposition of skirt portion 32 facilitatesstacking of lids 12 in telescoped relationship prior to utilization ofthe same.

Although tray 14 and lid 12 may be constructed of various types ofthermoplastic, heat-shrinkable, synthetic resin materials, best resultshave been obtained by utilizing orientated polystyrene of suflicientthickness to render tray 14 and lid 12 of self-sustainingcharacteristics, yet retaining'flexibility and resiliency so that thesame returns to its preformed shape upon deformation thereof in theabsence of heat.

It is also contemplated that the material from which tray 14 isconstructed be opaque in character, while lid 12 is transparent topermit the customer to view the product through area 28 of lid 12. Forthe marketing of poultry products such as dressed chickens, theattractiveness of thepackage is materially increased by utilizing ayellow pigment in the material from which tray 14 is formed.

In the packaging of a product such as a dressed chicken 34, the latteris placed within a tray 14 with the breast thereof facing upwardly, andthen one of the lids 12 is placed over the bird 34 in a manner so thatarea 2% complementally engages the upper surface configuration of thepoultry product. With the inner face of area 23 engaging the bird, itcan be seen that. skirt portion 32 is disposed in telescopingrelationship with respect to flange 24, and the defined marginalportions are in overlapping, abutting relationship, as best shown inFIG. 5. It is of importance to note that skirt portion 32 is of greaterwidth than flange 24 tothereby impart maximum utility to container 10and permit the same to be utilized to package chickens or the like ofdifferent weightsand employing lids 12 and trays 14 of a standard size.Tray 14 and lid 12, as illustratedand described, have been found to becapable of being utilized to package chickens ranging from one andthree-quarters to over three pounds without modification of thecontainer components in any way. It can be recognized however, thatdifferent size trays 14 and lids 12 may be provided for larger birdssuch as ducks, geese and turkeys and also for other meat or foodproducts. 7

Container 10, having the dressed chicken 34 therein, is now in conditionfor sealing with apparatus 16. Various heat-sealing machines may beemployed toefi'ect a proper seal between skirt portion 32 and flange 24of lid 12 and tray 14 respectively, but apparatus 16 as illustrated inthe drawings has been found to be of especial utility in providing thenecessary fluid-tight seal at a minimum cost and without deleteriouslyaffecting the appearance of the final sealed package.

Apparatus 16 includes a hollow housing 36 provided with a pair ofopposed side walls 38 and 4t; intercon nected by respective opposed endwalls 42 and .3. Top wall 44, carried by the upper margins of respectiveside walls 38 and 48 and end walls 42 and 43, has a pair of spaced,longitudinally aligned, rectangular openings 46 therein clearing theuppermost edges of corresponding heating elements 48. Parallel,horizontally spaced channels 58 spanning the distance between opposedside walls 38 and 40 adjacent the lower margins thereof, each carry apair of telescopic legs 52 depending therefrom and serving to supporthousing 36 in predetermined, spaced relationship relative to the flooror the like. Since legs 52 are extensible in character, the longitudinallengths thereof may be suitably adjusted to assure disposition ofhousing 36 in a substantially horizontal position.

Heating elements 48 each include a main body portion 54 of substantiallyrectangular configuration with the longest stretches thereofinterconnected by a cross section 56, whereby a pair of rectangularopenings 58 are presented in each of the heating elements 48 withopenings 58 being aligned longitudinally of top Wall 44 as best shown inFIG. 2.

Each of the body portions 54 and cross sections 56 of respective heatingelements 48 is of predetermined crosssectional configuration andincludes an upwardly extending, transversely triangular segment 68integral with main body portion 54. The outer face 62 of segment 60 issubstantially vertical and spaced inwardly from the outer vertical face64 ofmain body portion 54. The innermost surface 66 of segment 60 isdisposed at an angle with respect to face 62, with the diameter of theopening defined by surface 66 decreasing as main body portion 54 of eachof the heating elements 48 is approached. The inner surface 68 of mainbody portion 54 opposed to outer surface 64 thereof is disposed at anangle substantially complemental with that of side wall 20 of a tray 14to thereby provide clearance for tray 14 during the sealing operation.Angularly disposed surfaces 7% and 72 of main body portion 54 between arespective segment 69 and surface 68 thereof, present a substantially V-shaped groove 74 adapted to receive the edges of skirt portion 32 of lid12 and flange 24 of tray 14. Surface 78 is at an angle of approximately30 with respect to the horizontal, while surface 72 is approximately 45relative to the horizontal, with these angles being im portant to assureproper sealing of container 10. It is to be understood that grooves '74extend around each of the openings 58 of heating elements 48 and arethus formed in main body portions 54 and corresponding cross sections56.

It is contemplated that heating elements 48 be constructed by castingprocedures and therefore, it is preferred that integral mounting bosses75 be provided around the periphery of main body portions 54. Bosses'75, provided with suitable bolt-receiving apertures therein as shown inFIG. 11, are adapted to be secured to the underside of top wall 44 bysuitable bolt and nut means 76 extending through respective bosses 75,as well as spacers 78 between the lower surface of top wall 44 andrespective bosses 75. The upper ends of bolt and nut means 76 aresecured to or rest on the upper face of top wall 44.

A number of heating units 88 are embedded in each element 48 andpreferably of substantially U-shaped configuration and disposed atrespective corners thereof, as illustrated in FIG. 11. V-shaped heatingunits 82, embedded within corresponding heating elements 48 at the zonesof juncture of opposed ends of cross sections 56 with main body portions54, also provide heat at the corners of openings 58 defined by crosssections 56. Although heating units 88 and 82 may be of different types,the preferred units are of high resistance wire having power leads 84and 86 connected to opposed ends thereof and suitably coupled with anelectrical power system. A thermostat or thermocouple is also eithersecured to the outer surface of each of the heating elements 48 orembedded therein and operably coupled With leads 84 and 86 to controlthe flow of electrical current to units 81) and S2, and thereby maintaincorresponding heating elements 48 at a predetermined, selectivelyvariable temperature.

A generally horizontal inner wall 88 is provided within housing 36 andwelded or otherwise secured to the inner surfaces of side walls 38 and40, as well as end walls 42 and 43 in relatively close relationship tothe underface of top Wall 44. Wall 88 serves as means for mountingcontainer-supporting structure 90 provided for each of the openings 58in heating elements 48. Since structures fit) are identical inconstruction, only one of the same is illustrated in detail in FIGS. 5to 7 inclusive and the description will be limited to the structureshown.

Structure 98, as shown in FIGS. 5 to 7 inclusive, is carried by innerhorizontal wall 88 and includes a cylinder 94 disposed in concentricrelationship to an opening 92 through wall 88 and in direct alignmentwith a respective opening 58 in a proximal heating element 48. Flange 96on the uppermost end of cylinder 94 is disposed in abutting relationshipto the lower surface of wall 88 and is secured to the latter by aplurality of rivets extending through flange 96 and a washer 98overlying the upper surface of wall 88 in axial alignment With opening92.

The lowermost extremity of cylinder 94 is internally threaded andcomplementally receives an externally threaded bushing 182 having aflange 183 engaging the lower end of cylinder 94. Sleeve 184,reciprooa'bly carried 1by cylinder 94,. projects outwardly from bothends of the latter and has a pair of lock nuts 1% on the lower extremity thereof for limiting upward movement of sleeve 194 relative tocylinder 94 and thereby wall 88. A central section 185 of sleeve 1% isof lesser diameter than the upper part of the defined sleeve to presenta cylindrical area between section 185 and the inner surface of cylinder94, and which receives a coil spring 107 bearing against the upper edgeof bushing 182 and engaging the annular shoulder 189 of sleeve 184presented by the lower margin of the part of sleeve 104 of a diametersubstantially equal to the inner dimension of cylinder 94. Elon gatedslot 111 in the enlarged part of sleeve 184 above coil spring Hi7slidably receives a pin 112 extending through the side wall of cylinder94, whereby rotation of sleeve 1&4 about the longitudinal axis thereofis preeluded by pin 112.

The .upper extremity of sleeve 104 proiecting above washer 98, mounts anannular, transversely irregular plate 108 welded to sleeve 1694 inconcentric relationship thereto and serving as means for mounting asubstantially cup-shaped sealing tray member also in coaxialrelationship with cylinder 94 and sleeve 1%. The tray member 118 issubstantially rectangular in configuration and is adapted tocomplementally receive a tray id in telescoped relationship thereto.Bottom 114 of tray member 116 is secured to plate 188 by a series ofscrews 113 extending through bottom 114 and into plate 1198. Rectangularside wall 116 of tray member 118 has a generally upright sectionintegral with the peripheral margin of bottom 114, while the uppersections of wall 116 remote from bottom 11 flares outwardly in a mannercomplemental with the outer surface of side wall 20 of a tr ay 1 3.Ledge portion 118 of tray member 118 integral with the upper peripheralmargin of side wall 116 is disposed to receive the section of tray 14between side wall 20 and flange 24 thereof. V-shaped reinforcing segment128 integral with the outer margin of ledge portion 118 includes anouter, normally vertical section and an upturned, angularly disposedinner section 122 engagingthe underface of ledge portion 118. As bestshown in FIG. 8, section 122 is disposed at substantially a 45 anglewith respect to the horizontal and complementally engages surface 72when tray member is at the lower end of its path of travel. Note shouldalso be taken of the fact that the edge defined by the zone of merger ofsection 122 with the vertical Wall of segment is received at the bottompart of groove 74 at the juncture of surfaces 70 and 72.

' Bottom 114 of tray member 110 is also provided with an opening 124therein concentric with plate 108 and clearing an annular element 126Welded to the upper extremity of an elongated rod 128 rec'iprocablymounted in sleeve 104 for reciprocatory movement relative thereto. Arectangular platen 130 removably secured to element 126 by screws 132passing through platen 130 and into element 126, is substantiallycomplemental with bottom 114 of tray member 110 and has an upstandingstep 134 on one longitudinal margin thereof for limiting movement of acontainer 10 in one direction, as will be explained hereinafter.

' Rod 128 extends downwardly from the lower extremityof sleeve 104 andis provided with an elongated slot 136 therein slidably receiving a pin138 carried by and extending through sleeve 104 into slot 136 forpreventing rotational movement of rod 128 relative to sleeve 104 andthereby cylinder 94. r

Ram mechanism broadly designated 140 and mounted on housing 36 includesa cross member 142 disposed within housing 36 in direct underlyingrelationship to cylinders 94 and thereby rods 128, with vertical,substantially trapezoidal plates 144 welded to opposed ends of crossmember 142 being slidably received between spaced guide elements 146,suitably secured to the innermost faces of respective end walls 42 and43.

'Three cylinders 148 secured to the underface of inner Wall 88 inhorizontally spaced, depending relationship thereto slidably receiverespective rods 150 projecting upwardly through suitable openings in topwall 44 and adjustably connected at the lowermost ends thereof to crossmember 142. As indicated in FIG. 3, the lower, ex-' tcrnally threadedextremities of rods 150 pass through suitable openings therefor in crossmember 142, with lock nuts 152 on opposed sides of cross member 142serving to maintain respective rods 150 in predetermined relationshiprelative to cross member 142. A crossbar 154 removably carried by rods150 at the upper extremities thereof and in parallel relationship tocross member 142, carries a ram head broadly numerated 156 for each ofthe openings 58 in heating elements 48.

Each of the ram heads 156 is substantially cup-shaped and secured tocrossbar 154 by a bolt 158 extending upwardly through the bottom wall160 of a respective head 156 and into a proximal portion of crossbar154. The side wall 162 of each of the ram heads 156 is of rectangularconfiguration flaring outwardly from correspond ing bottom walls 160 andadapted to surround area 28 of a lid 12 as best shown in FIG. 7.Rectangular, laterally extending edge portions 164 integral with eachlower margin of a respective side wall 162 of ram heads 156 are disposedto engage the outwardly extending ledge part of each lid 12 serving tointerconnect area 28 with the upper margin of skirt portion 32 thereof.It is also to be seen that respective edges 164- are in direct alignmentwith proximal opposed ledge portions 118 of tray members 110. Externalribs 166 on the outer face of adapted to be pivotally received withinand carried by parallel, horizontally spaced, corresponding ears 176,welded or otherwise secured to the underface of inner wall 88. It cantherefore be seen that cylinders 172 depend from inner wall 88, with thepiston rods 178 thereof extending downwardly and pivotally onnected tocorresponding links 180, in turn connected at respective extremitiesthereof to cars 182 secured to and projecting outwardly from the innersurface of side wall 38 in substantial alignment with correspondingpiston rods 178. The ends of 1inks'180 opposed to ears 182 are pivotallyjoined to connectors 184 secured to and depending from crossmember 142,while piston rods 178'are'pivotally joined to links intermediate theends thereof. Fluid lines 186 and 188 communicating with the interior ofeach of the cylinders 172 at opposed ends thereof permit fluid to beintroduced into either end of the cylinders 172 and likewise, permittingexhausting of such fluid at the opposite ends thereof. Automatic controlmechanism broadly numerated 190 and schematically illustrated in FIG.10, is mounted within housing 36 and includes a relay 192 provided witha coil 194 connected to a power line 196 through a lead 198 having aswitch 200 interposed therein. The end of coil 194 opposed to lead 198is coupled with the contact 202 of a cam-0perated limit switch 215 by aline 205. The ganged switch poles 204 and 206 of relay 192 areelectrically connected through a lead line 208 which is in turn coupledwith power line 196 by a lead 210. Contact 212 of relay 192 adapted tobe engaged by pole arm 206 is connected to a contact 214 of acam-operated switch 216' by a lead line 217. The other contact 218 ofswitch 216 is connected to the contact 220 opposed tocontact 212 by line222. Contact 224 of relay 192 adapted to be engaged by pole arm 204 isopen, while'the opposed contact 225 is joined to solenoid 226 by line228 and to solenoid 230 by line 232. Solenoid 226 is grounded by a line234, while solenoid 230 is electrically coupled with the contact 236 ofcam-actuated limit switch 238 by line 240. Limit switches 215 and 238are grounded by respective lines 242 and 244, while the contacts thereofopposed to corresponding contacts 202 and 236 are open.

' Limit switch 216 is operably coupled witha combination timer and motor246 by lead line 248, and timer and motor 246 is in turn grounded byline 250.. The shaft 252 of -mechanism 190 operably coupled with theshaft ofmotor 246, carries, cams 254, 256 and 258 disposed to engagerespective switches 215, 216 and 238for shifting the latter betweenopposed contacts, as is clear from FIG. 10. The armature 260 of solenoid230 is connected to a valve262 for opening and closing the latter, whilethe armature, 264' of solenoid 226 likewise controls a valve 266. Valve262 is interposed in a fluid conduit 268 leading from fluid reservoir270 to a T 272 which is in turn each of the ram heads 156 reinforcesbottom wall 160 and side walls 162 thereof to prevent warping of edgeportions 164 and assuring an even pressure on the parts of containcr10positioned between edge portions 164 and opposed ledge portions 118during the sealing operation.

Mechanism broadly designated 168 for reciprocating coupled with fluidlines 186 leading to the upper ends of respective cylinders 172. Valve266. controls'flow o-f fluid through a line 274 from reservoir 270 to aT276 connected with lines 188 passing to corresponding lower ends ofcylinders 172. Supply line 278 connected to reservoir 270'serves todirect additional fluid into the latter, while fluid exhaust line 280 isprovided for permitting fluid to pass outwardly'from the definedreservoir.

In operation, it is to be understood that ram heads 156, platens 130 andtray members 110 are maintained at the uppermost ends of their paths oftravel, as shown in FIGS. 1, 3 and 5, with coil springs 107 biasingrespective sleeves 104 upwardly and cross member 142 engagingthe lowerextremities of rods 128 also maintaining platens 130 in spacedrelationship to tray members 110 and thereby heating elements .48.Switch 200 is also open and combination timer and motor 246 therebyinactivated. During this condition of apparatus 16, valve 262 is open topermit fluid to be exhausted from cylinders 172 through line 268 and viaexhaust line 280, while valve 266 is in a condi tion to permit fluid tobe directed through conduit 272 and thereby forcing piston rods 178toward the uppermost ends of their paths of travel and maintaining crossmember 142 in the position illustrated in FIG. 4, by virtue of thepivotal connection of piston rods 173 to respective links 180.

It is further understood that the operator of apparatus 16 has placedproducts to be packaged, such as a dressed chicken or the like, within atray 14 and then subsequently a lid 12 is placed over the poultry andtray 14, with skirt portion 32 of lid 12 disposed in overlapping,abutting relationship to flange 24, whereby tray 14 is telescoped Withinlid 12. The skirt portion 32 of lid 12 serves the additional importantfunction of guiding lid 12 onto tray 14 after a bird has been placed intray 14 and thus materially increasing the rate at which the poultryproducts may be packaged by virtue of the fact that the operator is notrequired to hold the packaging component in alignment prior to insertionof the same into the sealing apparatus.

At least four packages of the character set forth above are prepared andthe operator then slides the same into the space between respective ramheads 156 and platens 130 until side Walls 20 of trays 14 engagecorresponding stops 134. Thereupon, the operator closes switch 2% toenergize coil 194 of relay 192, whereby ganged pole arms 204 and 266 aremoved into contacting engagement with contacts 225 and 212 respectively.Timer and motor 246 is actuated by virtue of current passing through acircuit traced by power line 195, lead 21%, lead line 2118, switch arm206, line 217, contact 214, switch 216, line 248 and motor 246 to groundvia line 250.

It should be explained at this point that timer and motor 246 includesgearing for causing shaft 252 to be rotated at a substantially slowerspeed than the shaft of motor 246, whereby cams 254, 256 and 258 forcontrolling reciprocation of switches 215, 216 and 238 are likewiseturned at a relatively slow speed. At the time of initial actuation ofswitch 201) to close the circuit to relay 192, cams 254, 256 and 258are'disposed in the positions illus trated in FIG. to thereby maintainswitches 215, 216 and 238 in the dispostion shown.

Arm 264 of relay 192 is also shifted into engagement with contact 225whereby solenoid 231i is energized through a circuit traced by powerline 196, lead 210, lead line 268, arm 2G4, contact 225, line 228, line232, solenoid 230, line 2413, contact 236, switch 238 and line 244 toground. At the same time, solenoid 226 is also energized through line228 along the circuit traced above and to ground through line 234. Uponactuation of solenoids 230 and 226, valve 262 is opened, while valve 266is likewise opened to a position whereby fluid is directed intocylinders 172 from reservoir 270 via conduit 26% and supply lines 186.Simultaneously therewith, the fluid within cylinders 172 is exhaustedtherefrom via lines 183 and line 274 connected to reservoir 2'70 andwhich permits exhausted fluid to pass outwardly therefrom through fluidexhaust line 280. When timing motor 246 has rotated cams 254, 256 and258 for an elapsed period of approximately two seconds, cam 253 permitsswitch 238 to move to a position engaging the normally open contactopposed to contact 236 whereby the circuit to solenoid 230 is broken andcausing valve 262 to be closed as armature 260 is shifted under theaction of the spring within solenoid 230. Flow of fluid from reservoir2'71) to cylinders 172 via conduit 268 is thereby discontinued.

- The components described above are so constructed thaat after thetwo-second period during which fluid is di rected into cylinders 172,piston rods 173 are moved downwardly to cause link 180 to be pivotedabout respective ears 182. Swinging movement of the ends of links 180remote from ears 182 and joined to respective connectors 184 causescross member 142 to be shifted downwardly with plates 144 slidingbetween respective guide elements 146. Since rods 12S rest on crossmember 142, platens 130 connected to rods 128 move downwardly with thelatter and cause containers 15 to be lowered to a preheat positionillustrated in FIG. 6.

Skirt portions 32 of lids 12 and flanges 24 of trays 14 are therebymoved into sufiicient proximity to heating elements 43 to cause theoverlapped, abutting portions of container 10 to be softened withoutcausing substantial shrinkage or melting of the thermoplastic syntheticresin material.

It is also to be noted that as cross member 142 is forced downwardly bypiston rods 178 connected to respective links 185, rods 15% are alsoshifted downwardly to cause ram heads 156 to be moved into engagementwith respective lids 12 of containers 10. Edge portions 164 of ram heads156 engage the outwardly extending portions of lids 12 interconnectingthe central areas 28 thereof with skirt portions 32 and the definedoutwardly projecting portions of lids 12, as well as the proximalsections of trays 14, are compressed between edges 164 and sections 122of tray members 110. Thus, during the preheat period, the

containers 10 are received Within respective tray members 116 and ramheads 156 with the opposed peripheral margins thereof compressing theouter extremities of lids 12 and trays 14.

Cams 254, 256 and 258 are constructed so that when the same have beenrotated for an additional period of eleven seconds, cam 258 again closesswitch 233 by moving the same into engagement with contact 236 wherebysolenoid 230 is energized through the circuit set forth above. Thus,fluid is again directed into cylinders 172 as valve 262 is opened andfluid introduced into the upper ends of cylinders 172 via conduit 268and supply lines 186.

Piston rods 178 are thereby forced downwardly to the lowermost ends oftheir paths of travel and ram heads 156, engaging tray members throughcontainers 10 disposed therebetween, force tray members 110 and platensdownwardly against the action of coil springs 107 which engage bushings102 and are disposed to normally bias sleeves 164 toward the uppermostends of the paths of travel thereof as defined above.

As ram heads 156 force containers 10 downwardly to- Ward respectiveheating elements 48, skirt portions 32 of lids 12, and flanges 24 oftrays 14 are moved into contacting relationship with the sloping innersurfaces of faces 66 of upright segments 60. As previously described,heating elements 48 are maintained at a somewhat higher temperature thanthe normal melting point of the synthetic resin material ftom whichcontainers 10 are constructed, and therefore, skirt portions 32 andflanges 24 are subjected to such heat and thus, shrink andsimultaneously melt with consequent fusing of abutting portions of theremaining areas of skirt portions 32 and flanges 24.

Pressure is maintained on opposed, outwardly extending margins of lids12 and trays 14 by virtue of ram heads 156 being forced downwardly bypiston rods 178 and tray members 111) being biased upwardly under theinfluence of coil springs 107. Furthermore, since skirt portions 32 andflanges 24 of container 16 are disposed in overlapping relationship, theextent being dependent upon the size of the chicken 34 enclosed withincontainer 10, it can be be seen that a tight seal is produced regardlessof the degree of telescoping of trays 14 into corresponding lids 12.

An air and liquid-tight seal is formed between lid 12 and tray 14 eventhough portions of the bird may be disposed in the areas betweenoverlapping, outwardly projecting, marginal portions of lid 12 and tray14 respectively. Prior packages, wherein outwardly extending flangesdisposed in overlapping relationship were subjected to heat sealingoperations, many times leaked because parts of the bird were interposedbetween the normally overlapped flanges and thus prevented proper fusingof the packaging materials under the influence of heat. Openings wereproduced which permitted liquids within l. l the package to runoutwardly therefrom or air could pass into the package.

The configuration of grooves 7 in elements 48 is of importance toproduce the required seal between skirt portions 32 and flanges 24 ofcontainer it), and the defined angularity of the surfaces presentinggrooves '74 has been found to be of significance in producing properlysealed joints without subsequent leakage of fluid into the container orliquids out of the same.

During downward movement of ram head 156, the lower edges of danceportion 24 and skirt portion 32 tend to curl inwardly under theinfluence of'the heat from a respective heating element 43 and thus,when ram head 156 reaches the lowermost end of its path of travel, theouter peripheral portions of flange 24 and skirt 3?. are clamped betweensection 122 of sealing tray member H9 and surface 72 of groove 74. Thus,because of the heat shrinkable characteristics of the polystyrenematerial from which containers are constructed, the major excessmaterial of flange 2 and skirt 32 are caused to shrink and thereby fusetogether, but compression of the outer areas of flange 24- and skirtportion 32- between section 12 2 and surface '72. prevents shrinking ofthat part of lid 12 and tray 14 extendin downwardly from the outwardlyprojecting, parallel flange segments thereof and also small areas ofliange 2-4 and skirt 32 clamped between section 122 and surface F2. Thispermits air-tight sealing of each of the containers 1d and preventsshrinkage of respective flange portions 24- and skirt portions 32.thereof to such a degree as would otherwise produce an opening betweenthe components of the container. Upon upward movement of the platen 13%,relative .to tray member 11%), the curled, fused bead area of flange 2dand skirt 32 of container it is pulled loose fromthe downwardlyextending segment 12% of tray lit) by virtue of the relatively fieXiblenature of such fused head while the latter is still in a heatedcondition.

The sealed, outwardly extending edge of containers 32 formed by fusingof fianges 24 and skirt portions 32 presents a relatively rigid beadcircumscribing each container 1i and thereby imparting rigidity to theentire package. it is to be understood that the exact width of each ofthe skirt portions 32 and flanges 24 which are caused to be shrunk bythe heat sealing operation is dependent upon the size of the birdenclosed within respective containers it and the degree of overlappingof the defined skirt portions and flanges.

Furthermore, the configuration of trays l4 and li s 12 with curvedcorners has been found to be important in the production of a tightlysealed package, since the molten material may readily liow around thecorners notwithstanding the tendency of the material to bunch or overlapat the corners. Again, the heat-shrinking charac teristics of thesynthetic resin eliminates bunching of the material which would leaveopenings through which air or other fluids or liquids could pass.

The cam motor arrangement controlling opening and closing of switches215, 21-6 and 2398 is timed so that heads 156 maintain containers in asealing position, as best shown in FIG. 7, for approximately nineteenseconds. Thereupon, cams 254 and 156 have been rotated a sufficientdistance to permit both of the switches 215 and 216 to be shifted intoengagement with the lower proximal contacts, viewing FIG. 10, wherebythe circuit to coil 1% of relay 192 is broken and simultaneouslytherewith, switch 2H is shifted into engagement with contact 213. Thus,even though ganged arms 55% and 266 are permitted to shift to theirinitial positions, it can be seen that timing motor 245 continues tooperate by virtue of current passing to the same from power line 196 vialead 21%, lead line 233-, arm 2%, contact 22%, line 222, contact ZlS,switch 216 and line 243. g

This action permits air to be exhausted from cylinders 172 by virtue ofthe fact that valve 2%.?) is in a position permitting fluid to beexhausted through conduit 263,

while solenoid controlledvalve 266 is openedto alocation whereuponcompressed fluid may pass into the lower end of cylinders .172 via line274 and lines 188, whereby piston rods 1% are shifted toward theuppermost ends of their paths of travel.

During upward movement of piston rods 178, links 185) are again swungtoward their original positions about ears 182 and thus causing crossmember 142 to again be shifted upwardly. As cross. member 142 is raised,ram heads 156 are shifted upwardly by virtue of rods 159 sing moved withcross member 142, and at the same time, cross member 142 engages thelower extremities of rods 12% to force platens "13h totheir upperpositions substantially level'with top wall 44, whereby additionalcontainers 1 having products 34 therein may be placed beneath ram headsAlso, upon movement of ram heads 156 away from tray members 119, coilsprings 157' bias sleeves 1% and thereby tray members lit to theirpreheat positions. 7 I

Timing motor continues to drive shaft "252 until piston rods 178 haveben shifted to the uppermost ends of their paths of travel,whereuponcamldfi has been rotated to a position permitting switch2l 5 toshift into engagement with contact 218, thereby breaking the circuit tomotor 245 and inactivating mechanism 19%. i

The next cycle of operation willnotscomm'ence until switch 2% has againbeen closed by the operator.

An especially important feature of the invention is the disposition ofresistance heating units 39 and 72 in the positions best shown in FIG.11 and at the corners of openings 56, whereby betterdistribtuion of heatis provided and firm sealing of the corners of containers It} isefiec'ted. It has been found that by raising the temperature of thecorners'of skirt portions 32 andfianges 24' to a slightly higherpointthat the rectilinear stretches of such parts of containers 10, abetter seal is obtained at the corners and improved flow of the moltenmaterial is accomplished. g V V Having thus described the invention,what is claimed as new and desired to be secured by Letters Patent is:

1. Apparatus for sealing the overlapped, abutting marginal portions of apair of members of thermoplastic, heat-shrinkable material and adaptedto receive an article therebetween to present a package, said apparatusincluding a frame; a heating element on said frame and substantiallyconforming to the configuration of said marginal portions of themembers; a platen shiftably mounted on the frame, disposed to receivethe package in supporting relationship thereto and normally spaced fromthe heating element, the latter being disposed across the path of travelof said marginal portions when the package is supported on the platen,said platen being movable downwardly from a first location above theheating element to a second location permitting said marginal portionsof the members to engage the element; and a ram shiftably mounted on theframe, above said platen and movable downwardly from a positionsufficiently spaced from said first location of the platen to permitplacement of the package therebet-ween, to a disposition engaging thepackage and subsequently shifting the latter and thereby the platen tosaid second location thereof with the marginal portions of the memberengaging the heating element.

2. Apparatus for sealing the overlapped, abutting marginal portions of apair of members of thermoplastic, heat-shrinkable material and adaptedto receive an article therebetween to present a package, said apparatusincluding a frame; a heating element on said frame and substantiallyconforming to the configuration of said marginal portions of themembers; a platen shiftably mounted on the frame and disposed'to receivethe package in supporting relationship thereto, said heating elementbeing disposed within the path of travel of said marginal portions whensaid package is supported on the platen, the latter being movabledownwardly from a first location spaced above the element to a secondlocation permitting said 1 3 marginal portions of the members to engagethe heating element; means on said frame connected to the platen forshifting the latter toward said first location thereof andandsubsequently shifting the latter and thereby the platen to said secondlocation thereof with the marginal portions of the members engaging theheating element; and power operated means operably coupled with the ramfor shifting the latter to and from said disposition thereof.

3. Apparatus as set forth in claim 2, wherein said ram is provided withan edge thereon engageable with said marginal portion of a proximalmember for biasing the latter toward the opposed marginal portion of theother member to assure a firm bond between said marginal portions of themembers during melting and shrinking of the same by said heatingelement.

4. Apparatus as set forth in claim 2, wherein said heating element isprovided with a groove of dimensions to receive a part of said marginalportions of the members, said ram having a flange thereon disposed topress said marginal portions into said groove as the ram is moved fromsaid position of the same to said location thereof.

5. Apparatus for sealing the overlapped, abutting downturned flange andside margin portions of a polygonal tray and lid respectively formed ofthermoplastic, heatshrinkable material and adapted to receive an articletherebetween when in telescoped relationship and thereby presenting apackage, said apparatus including a frame; a ring-like polygonal heatingelement on said frame and substantially conforming to the peripheralconfiguration of said flange and side margin portions of the tray andlid respectively, said element being provided with a groove extendingaround the same in a position to receive said flange and side marginportions; a platen mounted on the frame for shifting movement throughthe heating element and adapted to receive the package in supportingrelationship thereto, said heating element being disposed within thepath of travel of said marginal portions when said package is supportedon the platen, the latter being disposed for downward movement from afirst location spaced above the element to a second location permittingsaid flange and side margin portions of the tray and lid respectively tobe received in said groove in the heating element; a ram shiftablymounted on the frame and movable downwardly from a positionsufli-ciently spaced from the first location of the platen to permitplacement of the package therebetween, to a disposition engaging thepackage and subsequently shifting the latter and thereby the platen tosaid second location thereof with the marginal portions of the membersengaging the heating element; and power operated means operably coupledwith the ram for shifting the latter to and from said dispositionthereof.

6. Apparatus as set forth in claim 5, wherein the surface of the heatingelement defining the innermost section of the groove therein is disposedat an angle relative to the normal disposition of said downturned flangeand side margin portions of the tray and lid respectively to therebyimprove the flow of the material during shrinkage and melting of thesame by said heating element.

7. Apparatus as set forth in claim 5, wherein means for heating saidelement includes electrical resistance units disposed at the corners ofsaid element.

8. Apparatus for sealing the overlapped, abutting marginal portions of apair of members of thermoplastic, heat shrinkable material and adaptedto receive an article therebetween to present a package, said apparatusincluding a frame; a heating element on said frame and substantiallyconforming to the configuration of said marginal portions of themembers; a platen shiftably mounted on the frame, disposed to receivethe package in supporting relationship thereto and movable from aposition spaced from the element to a location permitting said marginalportions of the members to engage the heating element; means on saidframe connected to the platen for shifting the latter toward saidposition thereof and away from the heating element; a ram shiftablymounted on the frame and movable from a position sufficiently spacedfrom the platen to permit placement of the package therebetween, to adisposition engaging the package and subsequently shifting the latterand thereby the platen to said location thereof with the marginalportions of the members engaging the heating element; a rod secured tothe ram and shiftably carried by the frame; and a selectivelyactuatable, double-acting piston and cylinder assembly engaging said rodfor reciprocating the latter to shift said ram, said assembly includinga component shiftably mounted on the frame and disposed to engage therod for reciprocating the latter, the piston of said assembly beingconnected to said component for moving the same and said platen beingprovided with rigid means thereon disposed to be engaged by saidcomponent for shifting said platen from a preheating point intermediatethe ends of the path of travel thereof to said position of the same,said point being in sufiicient proximity to said element to cause themarginal portions of the members to be softened without shrinking ormelting of the same when the package is maintained at said point for apredetermined interval by the platen and said ram.

9. Apparatus as set forth in claim 8, wherein is provided a cup-shapedtray member having a bottom, reciprocab'ly mounted on the frame andadapted to receive the tray and thereby said platen, and means operablycoupled with said tray member and carried by the frame for normallymaintaining said tray member in a disposition with said package at saidpreheating point when the platen moves into engagement with said bottomof the tray member.

10. Apparatus as set forth in claim 9, wherein said means normallymaintaining the tray member in said disposition thereof includes aspring interposed between the frame and said tray member.

11. Apparatus as set forth in claim 10, wherein said tray member has anupper flange segment adapted to support said marginal portion of aproximal package member and substantially complemental with the lowerperipheral edge of said ram to thereby compress certain areas of saidmarginal portions of the package members therebetween when the ram is insaid location thereof.

12. Apparatus for sealing the overlapped, abutting marginal portions ofa pair of members of thermoplastic, heat-shrinkable material and adaptedto receive an article therebetween to present a package, said apparatusincluding a frame; a heating element on said frame and substantiallyconforming to the configuration of said marginal portions of themembers; a platen shiftably mounted on the frame, disposed to receivethe package in supporting relationship thereto and normally spaced fromthe heating element, the latter being disposed across the path of travelof said marginal portions when the package is supported on the platen,said platen being movable to a location permitting said marginalportions of the members to engage the elements; a ram shiftably mountedon the frame and movable from a position sufiiciently spaced from thenormal position of the platen to permit placement of the packagetherebetween, to a disposition engaging the package and subsequentlyshifting the latter and thereby the platen to said location thereof withthe marginal portions of the member engaging the heating element; andmeans on said frame operably coupled with the ram and said platen formaintaining the package at a preheat position proximal to said heatingelement prior to movement of the platen and said package to saidlocation with the marginal portions of the same engaging said heatingelement.

13. Apparatus for sealing the overlapped, abutting 15 marginal portionsof a pair of members of thermoplastic, heat-shrinkable material andadapted to receive an article therebetween to present a package, saidapparatus including a frame; a heating element on said frame andsubstantially conforming to the configuration of said marginal portionsof the members; a platenshiftably mounted on the frame, and disposed toreceive the package in supporting relationship thereto, said heatingelement being disposed within the'path of travel of said marginalportions when said package is supported on the platen, the latter beingmovable from a position spaced from the element to a location permittingsaid marginal portions of the members to engage the heating element;means on said frame connected to the platen for shifting the lattertoward said position thereof and away from the heating element; a ramshiftably mounted on the frame and movable from a position sufiicientlyspaced from the platen to permit placement of the package therebetween,to a disposition engaging the package and subsequently shifting thelatter and thereby the platen to said location thereof with the marginalportions of the members engaging the heating element; and power operatedmeans operably coupled with the ram for shifting the latter to and fromsaid position and said location thereof, said power op- 16 erated meansincluding structure tor -interrupting movement of the ram duringshifting thereof in a direction to move said platen into said locationthereof at a point with said platen located in a preheating positionwith said marginal portions of the package'in sufiicient'proximity tosaid heating element to only soften the same Without causing substantialshrinkage or melting of the same.

14. Apparatus as set forth in claim 13, wherein is provided timer meansoperably ,coupled with said *power means for controlling the period oftime said ram maintains the package in said preheating position andsubsequently with the marginal portions thereof in engagement with theheating element,

References Cited by the Examiner UNITED STATES PATENTS 1,978,630 10/34Hesson 53353 2,712,717 7/55 Keller 53-36 2732,1116 1/56 Merrill 5 --".-23,060,652 10/62 Eckman 5342 X FRANK E. I BAILEY, Primary Examiner.

TRAVIS 'S. MCGEHEE, Examiner.

1. APPARATUS FOR SEALING THE OVERLAPPED, ABUTTING MARGINAL PORTIONS OF APAIR OF MEMBERS OF THERMOPLASTIC, HEAT-SHRINKABLE MATERIAL AND ADAPTEDTO RECEIVE AN ARTICLE THEREBETWEEN TO PRESENT A PACKAGE, SAID APPARATUSINCLUDING A FRAME; A HEATING ELEMENT ON SAID FRAME AND SUBSTANTIALLYCONFORMING TO THE CONFIGURATION OF SAID MARGINAL PORTIONS OF THEMEMBERS; A PLATEN SHIFTABLY MOUNTED ON THE FRAME, DISPOSED TO RECEIVETHE PACKAGE IN SUPPORTING RELATIONSHIP THERETO AND NORMALLY SPACED FROMTHE HEATING ELEMENT, THE LATTER BEING DISPOSED ACROSS THE PATH OF TRAVELOF SAID MARGINAL PORTIONS WHEN THE PACKAGE IS SUPPORTED ON THE PLATEN,SAID PLATEN BEING MOVABLE DOWNWARDLY FROM A FIRST LOCATION ABOVE THEHEATING ELEMENT TO A SECOND LOCATION PERMITTING SAID MARGINAL PORTIONSOF THE MEMBERS TO ENGAGE THE ELEMENT; AND A RAM SHIFTABLY MOUNTED ON THEFRAME, ABOVE SAID PLATEN AND MOVABLE DOWNWARDLY FROM A POSITIONSUFFICIENTLY SPACED FROM SAID FIRST LOCATION OF THE PLATEN TO PERMITPLACEMENT OF THE PACKAGE THEREBETWEEN, TO A DISPOSITION ENGAGING THEPACKAGE AND SUBSEQUENTLY SHIFTING THE LATTER AND THEREBY THE PLATEN TOSAID SECOND LOCATION THEREOF WITH THE MARGINAL PORTIONS OF THE MEMBERENGAGING THE HEATING ELEMENT.